Split conversations/+page.svelte (346 lines) into:
- ConversationFilterBar.svelte: person A/B typeaheads, swap button, date range, sort toggle
- ConversationTimeline.svelte: summary bar, chat bubbles, year dividers, new-doc link
Page drops from 346 → ~70 lines; navigation logic and filter state stay in the page.
Part of #75
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
